Citrate is a kind of organic acid with largest production annually around 1.7 billion tons and the demand is increasing for 3.5-4.0% each year. China is the largest producer and top exporter of citrate, and 53% of the citrate production annually is from China. Many study aimed to improve the production process of citrate fermentation. As the basis of fermentation, industrial strain improvement is also a focus of study. During citrate fermentation, A. niger absorbs glucose as carbohydrate resource. Torres examined that 2 Km existed during glucose absorption by A. niger, which were 260 μM and 3.67 mM, suggesting both high affinity and low affinity glucose transport system worked in A. niger. Furthermore, the low affinity glucose transport system provided the metabolite during citrate fermentation. Nevertheless, the system only worked when glucose concentration was above 50 g·L−1. Glucose transportation is the first step of citrate fermentation, and glucose transportation system is crucial for citrate production, thus adjust the glucose transport system may enhance citrate production.